What a funny boy, ________?
A. aren’t you
B. aren’t they
C. isn’t he
D. is he
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Which of the following tag questions is INCORRECT?
A. Carry this parcel for me, will you?
B. Nobody wants to go there, don’t they?
C. Some people know him, don't they?
D. Everything is ready, isn't it?
一根半埋于泥土中的铁管时间久后发现泥土中的部分铁管腐蚀严重,而暴露于空气中的部分腐蚀较轻,这种腐蚀称作。( )
A. 析氢腐蚀
B. 差异充气腐蚀
习惯上,称腐蚀电池的电极为阴极和阳极。阳极上发生()反应。
A. 氧化
B. 还原
钢铁在大气中主要发生析氢腐蚀。( )
A. 对
B. 错